English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Quantitative  29 Si NMR spectra of single-crystal a-quartz, shock compressed to 12-38 GPa and recovered, provide new information about the complex response of quartz to shock loading. Spectra from samples recovered from shock pressures of 12-20 GPa show a broadening of the  29 Si NMR peak and the development of asymmetry toward lower NMR frequency (indicating an increase in the mean Si-O-Si intertetrahedral bond angle). NMR spectra of samples shock compressed above ~ 25 GPa show increasing amounts of a separate amorphous phase of SiO 2  with a mean Si-O-Si bond angle roughly 5° narrower, and 10-15% denser, than fused SiO 2 . Small amounts of crystalline material remain with a mean Si-O-Si bond angle up to 3° larger than unshocked a-quartz. The recovery of dense glass indicates that post-shock temperatures were sufficiently low to also preserve stishovite, had any been created in our experiments. The paucity of stishovite or  [6] Si in an amorphous phase in our recovered samples suggests that the formation of stable, highcoordinated Si is kinetically hindered in shock compression experiments up to about 35- 40 GPa, except in regions of high temperature, such as planar deformation features (PDFs), microfaults (pseudotachylites), or voids.

Shocked quartz: A 29 Si magic-angle-spinning nuclear magnetic resonance study